Convertible fixed-wing paddle wheel aircraft



March 31, 1953 H. VAN ZANDT 2,633,311

CONVERTIBLE FIXED-WING PADDLE WHEEL AIRCRAFT File d Aug. '7, 1950 2SHEETS-SHEET 1 I /v VEN 70f? HENRI VAA/ZA/VDT [By/W gm March 31, 1953 H.VAN ZANDT 2,633,311

CONVERTIBLE FIXED-WING 'PADDLE WHEEL AIRCRAFT Filed Aug. 7, 1950 v 2SHEETSSHEET 2 5X A 77 R/VE) Patented Mar. 31, 1953 CONVERTIBLE FIXED-WING PADDLE WHEEL AIRCRAFT Henri van Zandt, Starke, Fla.

Application August 7, 1950, Serial No. 178,111

12 Claims.

This application is a continuation-in-part of my application Serial No.616,066, filed September 13, 1945, entitled Aeroplane Turbine ControlRotary Wing Jet Propulsion Turbine.

My invention relates to a heavier-than-air type of aircraft and moreparticularly to improvements in aircraft making use of airfoils whichrevolve about a shaft in the nature of a paddle wheel to provide liftingforce or horizontal driving force, or both.

The invention particularly contemplates improved means for controllingthe pitch of the airfoils during the revolution and to means foraligning the airfoils into parallel positions for operation of theaircraft as a conventional stationary wing aircraft.

A general object of the invention is to improve the pitch control of theairfoils of a revolving wing aircraft.

An additional object is to provide means to stabilize the revolvingairfoils into a predetermined parallel alignment for conventionalflight.

A further object of the invention is to provide a revolving wingaircraft particularly adapted for propulsion by a jet engine, in amanner such that the jet engine may be used for forward propulsion aswell as for the provision of the power necessary to revolve theairfoils.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My inventionitself, however, both as to its organization and method of operation,together with further objects and advantages thereof, may best beunderstood by reference to the following description taken in connectionwith the accompanying drawings, in which:

. Fig. 1 is a general view of a portion of an aircraft utilizingrevolving airfoils as it may appear in flight,

Fig. 2 is a detailed View of a mechanism adapted to alter the flightcharacteristics of the aircraft of Fig. 1 by adjusting the pitch controlmechanism,

Fig. 3 is a detailed view of an arrangement use- 111 in changing theaircraft from a condition for operation as a revolving wing aircraft toa condition for operation as a stationary wing aircraft,

Fig. 4 is a diagrammatic presentation of airfoil positions which may beassumed during flight of the aircraft,

Fig. 5 is a diagrammatic presentation of a modification respecting theshape of a guide ring whereby altered or improved operation may beobtained,'-and Fig. 6 is a detail view of a portion of the mechanismuseful in controlling airfoil positions.

Referring now to Fig. 1, the aircraft may comprise a fuselage or bodyportion l to which is afiixed a stationary bearing block 2 to support arotatable shaft 3. The body portion I further supports a guide channelor ring 4, which is adjustable in position on the body, and a strut 5.The strut 5 extends outwardly from the body to support at its outwardend a jet engine 6 and. further to support a bearing boss I in which theouter end of shaft 3 is free to rotate. Mounted to shaft 3, androtatable therewith, are two hubs 3 and 9 carrying spokes H], ll, [2, l3and M. An airfoil I5 is mounted between spokes l0 and H, spoke It beingpivotally attached at 16 to the outboard end of the airfoil and spoke llbeingv similarly attached to the inboard end of the airfoil. Airfoil I1is attached in the same manner to spokes l2 and I3 and airfoil I8 isattached to spoke l4 and to a second spoke extending from hub 9, notshown in the drawing. Each airfoil is provided at its inboard end withan upstanding arm [9 to which is attached a freely rotatable wheel 20for cooperation with the guide channel 4, the arm and wheel providing aguide follower.

The relative positions of the guide wheel 20, or guide follower, and ofthe axis established by the pivotal connections of the airfoil to thespokes establish the pitch of the airfoil.

Airfoils I5, 11 and it are revolved about the axis of shaft 3 by therotation of the shaft. The shaft is driven by a bucket turbine wheel 2I, attached to the shaft near its outboard end and cooperating with theexhaust of combustion products, indicated by the arrow 22, from the jetengine 6.

Guide 4 conveniently takes the form of a channel in which wheel 20 isconfined. The channel guide member 4 may be circular as shown in thedrawings, or it may be elliptical or egg-shaped. The guide is so mountedto the aircraft body I that it may be adjusted along the body in thefore and aft direction. Slots 2.3 and 24 are cut in the aircraft body topermit this adjustment. The guide is held against the body by flatheaded bolts 25 and 26 which extend through the back of the channel, theheads being flush therewith not to interfere with the wheels 20, andinto the body I through the slots 23 and 24. An adjusting arrangementwithin the body, later described in connection with Fig. 2, retains theinner ends of the bolts to hold the channel guide against the surface ofthe body.

In operationas a revolving airfoil aircraft, jet

3 engine 8 is supplied with fuel preferably through strut and withelectrical ignition energy through the strut to a spark plug 21 arrangedto explode the fuel in the combustion chamber portion 28 of the engine.The jet engine may take in air through a forward opening 29 to be mixedwith fuel in the combustion chamber, to be exploded by spark plug 21,and to exhaust thecombustion products through a jet tube 30. The jetengine is, preferably, of the type known as a reso-jet making use ofvibrating reeds at the forward end of the combustion chamber which admitair during the interval between explosions thrust is applied throughstrut 5' tothe aircraft and the exhaust products are expelled in thedirection of arrow 22 against the lower portion of the bucket turbinewheel 2| to drive shaft 3 in a counter-clockwisedirection as seen inFig. 1. This rotation of shaft 3, in bearings 2 and 1, revolves theairfoils about the axis of shaft 3 to provide lifting force or forwardthrust, or both. As the airfoils revolve, the wheel in cooperation withguide 4 changes the pitch or angle of attack of the individual airfoils,since the axis o'ffsha'fti3 and the center of the circular guide are notcoincident. With a circular guide, its center should be slightly aft ofthe axis of shaft 3 in normal operation. The amount of lift, and theamount of forward motion of the aircraft, provided by the. revolvingairfoils, is adjusted by changing the relative positions of the axis ofshaft 3 and the center of the guide, the adjustments being made bymoving bolts 25 and 26 along the slots 23 and. 24, respectively.

The main guide 4 further comprises two sec ondary or branch channels, ofwhich only channel 31' is visible in Fig; 1, so' arranged in thepresent. instance that two of the airfoils may be abruptly'changed inpitch and aligned with the third airfoil to present the same angle ofattack for flight in the manner of a conventional aircraft. The branchchannel 3i is joined to, or is. derived from, the main guide channel 4-at a predetermined part of the main channel. When airfoil I8 is in theposition shown in Fig. 1, the Wheel mounted to its arm 32 maybe admitted into branch channel 3!, and when the wheel attached to arm 32,after following the branch channel for its restricted length, seatsagainst the closed end 33 of the branch chem-- nel; the'airfoil l8 willbe aligned with airfoil l5. A similar secondary branch or derivedchannel, not shown in Fig. 1, is provided for the wheel controlling thepitch of airfoil H to permit it to assume a, parallel alignment, and topresent a parallel angle of attack for conventional flight.

Fig. 2 discloses the mechanism disposed within the aircraft body throughwhich adjustments to the position of guide 4 are accomplished. As shownin this figure, a yoke or Y-shaped strap member 33 is arranged to lieflat against the inner wall of the aircraft body I. Bolts 25 and 26extend through slots 23 and 24 and through the end portions of the legs34 and 35, respectively, of the yoke member 33'. Nuts 33 and 31 arelocated on the bolts to hold the yoke member to the guide channel member4. Legs 34 and 35, lying flush against the inner side of the wall ofbody member I, thus hold channel 4 tightly against the outer side of thewall of body I. The portion 38 of the yoke member extending from-legs 34and passes undera suitable bracket 39 and is attached near its end to alever 40. This lever is pivoted at a point M to the body of the aircraftand may be moved in the directions of the arrow 32 to slide the yokeback and forth. This motion of the yoke slides bolts 25 and 26 in slots23 and 24 and moves the channel fore and aft into a desired position. Asuitable detent or locking mechanism can be arranged to hold theyoke inits selected position, but for the sake of clarity, such detentmechanism is not shown.

Fig. 3 shows a portion of the main guide channel' 4 and a portion of thebranch channel 3| together with a mechanism arranged to permit theguide. follower wheel of an airfoil to travel into the branch channelwhen desired, and to prevent the wheel from entering the branch channelwhen revolving airfoil flight is desired. To accomplish this purposethere is provided a door, shutter or deflector 43 hinged inside thechannel at the, intersection by a hinge 44- and firmly attached to a rod45 When the door' 43 is in the position indicated by solid lines in Fig;

3,.extending across the main guide channel, the- Wheel of an airfoilapproaching in the direction of arrow 46 will bedeflected into thebranch channel 3|, whereas the wheel will not be de-- fiected when thedoor 43" is in the position indi-- nels provided in an aircraftaccording to the de scribed embodiment of 'myinvention, which uti--lizes three airfoils on each side of the aircraft body, the controlcable 4'1' is preferably arranged to operate doors controlling theentrance ofwheels into each of the branch channels simultaneously orsubstantially simultaneously.

The diagrammatic representation of Fig; 4- indicates the positions ofairfoils l5, l1 and IS in solid lines as they may be at one instantduring' revolving airfoil flight. tached to airfoil I5, and the pivotalconnection of this airfoil at point I6 tospoke l0, maintain the airfoilin the position shown, and. the position of wheel 48' attached toairfoil l8, to-

gether with the position of pivot point 49' on spoke I4, determine theorientation or pitch angle of airfoill8. sitions of wheel 50 and pivotpoint 5| determine the pitch angle of airfoil [1. It will be noted thatdoor 43, guarding the entrance to branch channel 3|, and door 52guarding the entranceto branch channel'- 53', are each in closed posi--tion. Had door 43 been in the position indicated by'dotted'line' 54 anddoor E52 in the position indicated by dotted line 55 at the timethat-wheels 48 and 50 reached the entrances of channels 3| and 53,respectively, the wheels 48 and 50 would have been forced or shuntedinto thein Fig. 4, although a suitable" locking arrange ment may bedesirable to hold the airfoils in the aligned or parallel positions.Such" a look The wheel 20 at- Similarly, the relative po-- ingarrangement may take the form of solenoid operated catches, actuatedfrom within the aircraft body by suitable electrical connections, or,alternatively, mechanically operated catches or controls may extendthrough the wall of the aircraft body adjacent branch channels 3! and53.

While forward motion of the aircraft will tend to force airfoils H and18 into the aligned positions shown in dotted lines in Fig. l, a lockingand control mechanism is preferably provided, which may comprise an arm50' having a forked end of which the longer finger 5| is pushed alongguide 3| by the shaft of wheel 48 when the airfoil is forced back by theforce of the air, with the door t3 open, whereby the arm 50' is movedfrom the solid line position to the dotted line position of Fig. 4, asthe airfoil moves to position 56. Finger 52' prevents the airfoil frommoving from its position 56 until the arm 50 is rotated back to thesolid line position, and in being so rotated, the airfoil guide followeris again forced, by finger 5 I, into the main guide t.

It will be noted that the axis of shaft 53' about which arm 50 pivots isslightly removed from the center of curvature of the arc represented bybranch guide channel 36 whereby the shaft which mounts guide followerwheel 48 enters the slot between fingers 5i and 52' only after a shorttravel down the branch guide. The longer finger 5! is proportioned toprevent this shaft under any circumstances to pass beyond this finger.

This arrangement is further shown in Fig. 6, which is a side view of themechanism for controlling the airfoil it in the guide 3|. Most of theparts shown in Fig. 6 have been heretofore explained and are identifiedby the numerals used in connection with Figs. 1 through 4. Arm 5!! isshown connected to a shaft 53' terminating in a hand-operated leverportion 54 to rotate I the shaft. Rotating shaft 53, which is mounted ina suitable bearing through the wall of body I, will sweep arm 50' alongsecondary guide 3|. The arm 50' is swingable far enough in the onedirection to force shaft 55, which carries guide wheel 4'6 and is a partof the guide follower for airfoil member 18, into the main guide channel4 and, in the other direction, far enough to hold the wheel at the innerend of the branch channel for parallel airfoil flight. Suitable lockingmeans for lever 54, such as are indicated at 56, are preferablyprovided. A similar arrangement may be provided for each branch channelof the aircraft.

It is thus possible to change from conventional to revolving bladeflight, prior to landing, for example, or upon engine failure to operatethe craft as an auto-revolving blade aircraft to provide a slow rate ofdescent.

With the airfoils aligned, making use of the branch channels, the jetengine shown in Fig. 1 may be used for forward propulsion of theaircraft and if desired, a slight adjustment of the position of theengine may be made to direct the stream of combustion products below ortoone side of the turbine wheel, thereby to prevent burning of the lowerpart of the turbine wheel, which will be stationary, of course, duringconventional flight.

An important aspect of my invention comprises the location of the guidemember 4 outside of the normal positions of the airfoils, that is, themain guide is arranged entirely outside of the ends of spokes H], ll,l2, l3 and i4. .Being so located, the guide may be of light constructionbut will provide firm control of the airfoil orlentation with a minimumof friction. It is further possible with this construction readily toprovide any desired change of pitch of each airfoil as it rotatesthrough its orbit. An almost infinite variety of shapes for the mainguide, varying from circular to elliptical or egg shapes, may beprovided to produce with a high degree of accuracy the exact angle ofattack desired at each position throughout the revolution.

In revolving airfoil aircraft of the general type to which my inventionherein appertains it has been possible to vary the airfoil pitch duringeach revolution as a simple function, such as a sine function, of theposition of the airfoil about the axis of revolution. The large overalldimensions of the guide according to my invention, and the manner inwhich the guide operates to control the pitch, however, make it possiblereadily to select any pitch which may be desired at each position in theorbit of the airfoils.

It has been previously known that a sinusoidal variation in the pitchangle, that is, the angle presented between the tangent to the circle ofrevolution of the airfoils and the airfoil surface, in revolving wingaircraft, results in some loss in efficiency due to a departure from theangle of attack of the airfoil throughout substantial portions of acycle from the aerodynamically correct angle. Since for relatively lowforward speeds a sinusoidal variation approximates the most desirableconditions, a sinusoidal variation may be successfully employed in myinvention and such variation will result from the use of a circularguide, as shown in Figs. 1 and 4. The adjustment of the guide to disposeits center in various positions with respect to the axis of revolutionof the airfoils provides a method of adjusting the lift and forwardthrust provided by the airfoils. To convert the craft for high speedoperation, however, means comprising the secondary or branch channelsare provided to convert the aircraft into a stationary wing triplane. orsimilar aircraft, for conventional flight.

It is a simple matter, moreover, further to improve the operation atrelatively low speeds by utilizing, as shown in Fig. 5, a main guidewhich is cam shaped and not circular.

In Fig. 5, for example, a non-circular guide 53 is shown which may takethe place of the circular guide heretofore described. This noncircularguide may provide a somewhat slower change in the pitch of the airfoilin travelling across the upper arc of its orbit and a more rapid changeof pitch as it starts downward in the forward arc of its orbit. The mosteffective shape of guide may be calculated for a given set ofcircumstances to meet the particular requirements or may be found byexperimentation. The desired pitch is then readily reproduced byconstructing the guide with the proper separation from the circular path59 defined by the pivot points mounting the airfoils to the armsextending from the central shaft, and the desired rate of change ofpitch during each part of the revolution is automatically obtained. Theguide is, of course, preferably formed without corners which might causeexcessive vibration but is rather smoothly curved.

The exact mathematical computation of the proper pitch of the airfoilsat each position in the cycle of revolution may be made in accord withthe discussion in United States Patent No. 2,123,916, issued July 19,1938, to Adolph Rohrback and entitled Aircraft. Once the desiredagcsas-ir wheel, is drawn in the required direction to es-' tablish. theposition of' the point 62 necessaryto provide the desired: or correct.pitch angle :cof the. airfoil. This: is repeated ata number of positionstolocate a. number of point positions for thecenter 62xthroughout theorbit. A guide may then. be constructed of. the shape. necessary toposition the center. of the follower wheel at the points .62. soestablished throughout. the. orbit.

Branch channelsEB and 61% for the purpose of converting the aircraft toconventional flight conditions are preferably provided in the channelregardless of the shape of the channel as heretofore described andv asindicated sche= matically in Fig. 5.

It will be understood that the complete aircraft will. comprise a secondgroupof airfoils. for the starboard side of the fuselage which is.

similar. tothe port side group shown in the figures;- and a second jetengine on the starboard side of. the fuselage is also provided. It ispreferred that" the shaft tshould extend through the fuselage-to form.the axis'of both sets of airfoiis' and to be driven by the turbinewheels'on both sides of the fuselage. It will be further understood thatthe fuselage l of Fig. 1'. carries stabilizers, elevators and a fin andrudder near the tail, not shown, each of which may be of conventionalconstruction and which are useful for the usual purpose during'flight ofthe aircraft, with the airfoils' arranged either for conventionalflightor for revolving airfoil flight.

While the invention is specifically described as applied to an aircraftcomprising two sets or groups'of three airfoils each, one such set beingdisposed'onieach' side; two airfoils only may make up. each set or agreater number may be employed, and any even number of sets may be used.One jet engine; centrally located, may' prove-sufficient, although anumber greater-than two; as described, may bedesirable;

While. I have shown only certain preferred embodiments of my inventionby way of illustration,.many modifications wil occur to those skilledinthe art, and I therefore wish to have it understood that I intend, inthe appended claims,.tocover all such modifications as fall within thetrue spirit and scope of my inven-=- tion.

WhatIclai'm as new and desire United StatesLetters Patent is 1;.In anaircraft comprising a plurality of airfoil members arranged for bodilyrevolution about anormally horizontal axis of revolution parallel tosaidairfoils and perpendicular to the direction of .fiight andhavingmeans to mainto secure by tain apredetermined portion of' each saidair-- foil members. at a predetermined distance from said axis; thecombination of a guide extending continuously around said axis, a guidefollower member attached to each said airfoil member 00-operatingwithsaid guide at points respectively remote. from saidpredetermined portions, a secondary guide. branching from said firstguide and positioned and arranged to dispose one saidairfoilmemberparallelto another said member 8.. when the follower memberof. said: onemember; has traversed.saidsecondary. guide, and adeflector; selectively operable. to shunt one said follower memberintosaid secondary guide.

2. An aircraft according. to claim 1 wherein said guide is locatedentirely outside the circularpath' of said predetermined portions.

3; An aircraft according to claim l including.

means to adjust the position of said guide. in respect to said axis.

4. In an aircraft having a fuselage and aplurality of aerodynamicallyprofiled, pivotallysup--' ported airfoils revolving bodily in asubstantiallycircular path about a normally horizontal axis. ofrevolution parallel to said airfoils transverseto the. direction offlight, the combinationof a continuous main guide channel, a guidechannel. follower attached to each airfoil cooperating with said mainguide channel to vary the pitch of said airfoils durin each revolution,means for adjusting the position of said guide channel relative to saidaxis to alter the variations of pitch of said airfoils, a secondaryguide channel branching from said main channel at a position, and of adirection, shape and extent,

such that an airfoil whose follower follows said secondary channel willbe positioned parallel to another said airfoiLand a deflector adjustablein position selectively to block said main channel I and deflect one ofsaid followers into said secondary channel as itreaches said position atwhich said secondary channel branches. from said main channel or toblock said branch channel whereby said followers continue to follow saidmain channel.

5.- In an aircraft comprising a fuselage and a plurality of. airfoilmembers, a normally horizontal shaft extendingtransverse to thedirection of flight laterally from a side of said fuselage, a.

bearing on said fuselage mounting said shaft, a turbine rotormountedonsaid shaft, a jet propulsion device mounted on said fuselage inposition to direct combustion products thereof aftwardly' against aportion of said rotor to drive said rotor and rotatesaid shaft in saidbearing, members attached to said shaft for rotation therewithextendingw radiaily outwardly therefrom andpivotally supportin saidairfoil members at apredetermined distance from said shaft, a.continuous. guide member adjustably mounted to said fuselage surroundingsaid shaft and hav ing a minimum radial spacing from said shaft greaterthan said distance, a guide following member rigidly connected to eachsaid airfoil member cooperating with said guide memberat a-point remotefrom the pivotal mounting point of the respective-airfoil member therebyto control the angle of attack thereof, said points'for' being spaced bya pie-- each said airfoil member determined fixed distance, a restrictedlength branch guide-extendin in a predetermined direction-from apredetermined point'of said guide member-and shaped in the form of anarc, the

radius of curvature of said are being equal to said fixed distancaand adeflecting member se lectively operable. into position to permit saidguide: following members. uninterruptedly to 6. In an aircraftcomprisinga plurality of air'- foilmembers.revolvable bodily about anormally"horizontal axis parallel to said airfoil members and perpendicular tothe direction of flight and means to maintain a predetermined portion ofeach said member at a fixed distance from said axis, a guide followerattached to each said airfoil member, a non-circular continuous guidemember surrounding said axis and followed by a point of said followerremote from said portion of the respective airfoil member thereby tocontrol the pitch of said airfoil members throughout the orbit ofrevolution thereof, said guide being shaped to provide effectiveness foreach position of each said airfoil member for a predetermined selectedflight condition, a secondary guide branching from said first guidemember along which said point of said follower of one said airfoilmember may follow, said secondary guide being proportioned and arrangedto dispose said one airfoil member parallel to another said airfoilmember for conventional flight in response to said following by saidpoint of said secondary guide for a predetermined distance along saidsecondary guide, and means operable selectively to shunt one saidfollower point along said branch or to guide said follower points alongsaid first guide member.

7. An aircraft according to claim 6 wherein said first guide member isproportioned to lie everywhere outside of said fixed distance from saidaXlS.

8. An aircraft according to claim 6 wherein said first guide member isadjustable in position with respect to said axis in a directionperpendicular thereto.

9. In an aircraft comprising a plurality of airfoil members arranged forbodily revolution about a normally horizontal axis parallel to saidairfoil members and perpendicular to the direction of flight and havingmeans to maintain a predetermined portion of each member at apredetermined distance from said axis, the combination of a main guideextending continuously around said axis, a guide follower memberattached to each said airfoil member cooperating with said main guide atpoints respectively remote from said predetermined portions, a secondaryguide branching from said main guide and positioned and arranged todispose one said airfoil member parallel to another said member when thefollower member of said one member has traversed said secondary guide,and a member contacting a portion of said guide follower member whensaid last member is in said secondary guide movable to force said lastmember toward said main guide.

10. An aircraft according to claim 4 including i a member operable atsaid secondary guide channel to engage said follower and to move saidfollower from said guide channel into said main channel.

11. In an aircraft comprising a fuselage and a plurality of airfoilmembers, a normally horizontal shaft extending transverse to thedirection of flight laterally from a side of said fuselage, a

bearing on said fuselage mounting said shaft, a turbine rotor connectedto said shaft, a jet propulsion device carried by said fuselage andarranged to drive said rotor to rotate said shaft in said bearing and topropel said aircraft forwardly in response to the expulsion of exhaustgases therefrom, members attached to said shaft for rotation therewithextending radially outwardly therefrom and pivotally supporting saidairfoil members at a predetermined distance from said shaft, acontinuous guide member mounted to said fuselage surrounding said shaftand having a minimum radial spacing from said shaft greater than saiddistance, a guide following member rigidly connected to each saidairfoil member cooperating with said guide member at a point remote fromthe pivotal mounting point of the respective airfoil member thereby tocontrol the angle of attack thereof, said points for each said airfoilmember being spaced by a predetermined fixed distance, a restrictedlength branch guide extending in a predetermined direction from apredetermined point of said guide member and shaped in the form of anarc, the radius of curvature of said are being equal to said fixeddistance, and a deflecting member selectively operable into position topermit said guide following members uninterruptedly to traverse saidguide member or to force one said guide following member as it reachessaid predetermined point of said guide member into said branch guidethereby abruptly to change the angle of attack of the airfoil memberattached to said one guide following member.

12. An aircraft according t claim 1 comprising a jet propulsion unit, aturbine rotor operative at said axis normally to revolve said airfoilmembers bodily about said axis, said jet unit being mounted in front ofsaid rotor and oriented to direct exhaust gases in an aftwardlydirection at said rotor to cause rotation thereof, whereby forwardthrust to said aircraft is provided by said jet unit during flight as arevolving airfoil aircraft, and as a stationary wing aircraft when saidairfoil members are aligned.

HENRI VAN ZANDT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

